What is it? Good question. It looks like some sort of futuristic Speak & Spell/Etch-a-Sketch hybrid – a square of silver tubing framing a translucent grid, upon which an eye-tickling array of lights are constantly rearranged into patterns. The Tenori-on is actually part-live sequencer, part-synthesizer, part, well, toy.

How does it work? The main instrument is a 16-by-16 grid of backlit LED switches. Pressing or holding these switches maps sequences of notes or beats – represented visually by patterns of light. But really, the best way of getting your head round the Tenori-on, short of having a bash on one yourself, is to watch one of the many YouTube tutorials.

Where does it come from? The device is the brainchild of the Japanese interactive media artist Toshio Iwai. Yamaha launched the Tenori-on commercially (in the UK only) in December 2007.

Why is it classic? Just look at the damned thing! It's beautiful, an instant fetish object that makes you want to believe the wallet-torturing £749 price tag is somehow justifiable.

What's the best ever Tenori-on song? It's a bit too early to say really. The first ever Tenori-on album was only released in May 2008. (Its creator is a man called Norman Fairbanks and you can download it for free from his website.) We quite like Little Boots' regular Tenori-on renditions of chart hits like Ready For The Floor and Time To Pretend, though.

Five facts and things!

1. In spirit, the Tenori-on is a continuation of the many beautiful interactive sound and light generation installation pieces that Iwai has worked on since the mid-1980s.

2. Tenori-on too expensive? Make your own Tenori-off! Out of, er, bubblewrap. Better still, just download PaklSound1 – an app for the iPhone modelled closely on the Tenori-on.

3. As well as the standard "modes" of the Tenori-on interface – Score, Random, Draw, Bounce, Solo and Push – there are a host of secret modes that the user has to "unlock". Most of these features are yet to be discovered.

4. Somewhat predictably, Björk incorporated the Tenori-on into her Volta world tour, alongside the similar Jazzmutant Lemur and the exotic and unavailable-to-the-public Reactable.

5. As innovative as the interface is, the device has taken some stick from gearheads quick to point out its sonic limitations, who have dismissed the Tenori-on as a bit of a pretty gimmick.